WoodWorks Leads Blast Testing Project For Cross-Laminated Timber

by | Dec 19, 2016 | News

Videos are now available showing a series of live blast tests on three cross-laminated timber (CLT) structures at Tyndall Air Force Base, conducted by WoodWorks in cooperation with the US Forest Service and Softwood Lumber Board. Post-test observations were exciting. All structures remained intact and matched modeling predictions with acceptable levels of damage under significant explosive loading. The results of this testing will be used to further expand the use of wood solutions for Department of Defense applications and other blast-resistant construction. Watch the videos here: https://bit.ly/2hwVE1g

The CLT structures—each two-story, single-bay structure with anchorage to an existing concrete slab—were constructed in full by Lendlease over a period of eight days. Each structure was constructed using a different grade of CLT (i.e., grade designations V1, E1 and V4 per ANSI/APA PRG-320 provided by DR Johnson, Nordic and SmartLam, respectively) and included window and door openings (with doors provided by American Direct) consistent with an actual building. Self-drilling screws provided by MyTiCon and adhesive anchors provided by Hilti were utilized in concert with angle steel to connect the constituent panels of each structure.

Three shots were performed to demonstrate the effectiveness of CLT over a spectrum of blast loads. The first two shots were designed to stress the CLT structures to within their respective elastic limits. The third shot was designed to push the structures beyond their elastic limits such that post-peak response could be observed. Reflected pressure and peak deflections were recorded and will be used to thoroughly document the response of the structure in time, and support a design methodology for predicting elastic response of CLT under dynamic loads.

Initial observations deriving from these tests are positive. For the first two tests, peak recorded deflections were consistent with pre-test predictions, indicating the efficacy of the design assumptions and supporting design methodologies. Results from the third test indicated a controlled response in which localized panel rupture was observed but connection integrity and load carrying ability were not compromised for any of the three structures. Over the next couple months, WoodWorks will be working with Karagozian & Case, Inc. and the University of Maine to thoroughly post-process and analyze the results of these tests.

From Business Wire: https://www.businesswire.com/news/home/20161215005337/en/WoodWorks-Leads-Blast-Testing-Project-Cross-Laminated-Timber

Newsmakers 2016: DR Johnson Lumber Company

by | Mar 7, 2016 | News

DR Johnson Lumber Co., based in the small Oregon town of Riddle, is poised at the forefront of what could be a revolutionary use of wood as a building material in the Northwest.

Don R. Johnson founded the mill in 1951. Following his death in 2010, his daughters Valerie Johnson and Jodi Westbrooks decided they needed to move the millworks company in a new direction. Their father had been quick to jump on laminated beam products early on and the millworks had manufactured them for decades. Following the lead of their father’s eye for innovation, Valerie and Jodi decided to expand the mill’s manufacturing through a division called Riddle Laminators to include a new product they had heard about.

They have since invested millions of dollars in machinery that is allowing DR Johnson to become the first manufacturer in the country certified to produce cross-laminated timber panels – a new take on existing technology and products in the wood construction industry. What makes their product so progressive is the use of new-growth softwoods like Douglas fir to produce lighter, stronger, more flexible panels in sizes able to make the construction process much more efficient. They also offer a replacement to typical steel or concrete framing.

“We’re limited to 10-foot-by-32-foot panels because of transportation issues, but we can go larger if we need to,” said Todd Black, DR Johnson sales manager. “We have computer-controlled router systems that can pre-cut door and window openings, so the panels come prefabricated, labeled (for point of installation) and ready for immediate installation. Because they’re stronger and lighter than steel or concrete, we’re not limited to three or four stories as wood-frame construction would be.”

CLT is starting to capture attention in Portland. A 12-story structure under construction in the Pearl District will be the tallest all-wood building in the U.S. The technology has already been used successfully in Europe, where buildings up to 22 stories have been constructed with the same type of panels.

From DJC Oregon: https://djcoregon.com/news/2016/03/03/newsmakers-2016-dr-johnson-lumber-company/